:root {
  --primary: #1a3557;
  --secondary: #2e6b9e;
  --surface: #f4f6f8;
  --on-surface: #1a1c1e;
  --muted: #5c6670;
  --border: #d8dee6;
  --card: #ffffff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--on-surface);
  background: var(--surface);
  line-height: 1.5;
}

a {
  color: var(--secondary);
}

header {
  background: var(--primary);
  color: #fff;
  padding: 1rem 1.5rem;
}

header a {
  color: #fff;
  text-decoration: none;
  margin-right: 1rem;
  font-weight: 600;
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.tier-grid {
  display: grid;
  gap: 1rem;
}

@media (min-width: 720px) {
  .tier-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.tier-grid .card.featured {
  border-color: var(--secondary);
  box-shadow: 0 0 0 2px rgba(46, 107, 158, 0.2);
}

.price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.toggle-row button {
  border: 1px solid var(--border);
  background: var(--card);
  padding: 0.5rem 1rem;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 600;
}

.toggle-row button.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  text-decoration: none;
  padding: 0.65rem 1.1rem;
  border-radius: 6px;
  font-weight: 600;
  border: none;
  cursor: pointer;
}

.btn-secondary {
  background: var(--card);
  color: var(--primary);
  border: 1px solid var(--primary);
}

footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--muted);
  font-size: 0.85rem;
}